Microbiology Lab Report

Decent Essays
Various test performed to identify two bacterium that were unknown, one was plaque that were scrapped from the teeth and the second was an unknown given. It resulted that the unknown bacterium is Staphylococcus epidermidis. Staphylococcus epidermidis has three drug resistance, and no secondary metabolites. The plaque scrapped from the teeth had a morphology of bacilli and is gram positive. Staphylococcus is gram positive, it is catalase positive and oxidase negative. The minimal inhibition concentration of Ethanol extract is 0.001 micro liters for S. epidermidis. The minimal inhibition concentration for the plaque was at a concentration 0.1 ml of ethanol extract and a concentration of 0.01 ml for distilled water.
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Oxidase Test: Using a sterilized loop inoculate a loopful of bacteria into the test square and observe for any change in color. If it turns blue it is oxidase positive, and if it remains the same color then it is oxidase negative.
Streaking: Using the method of quadrant streak a loopful of bacteria onto one side of the BHI agar plate and sterilize your loop. Then using the sterilized loop, grab one end of the side where it was previously streaked and slide it across on another side of the agar plate. Then using the sterilized loop grab the one end of that same side where it was previously streaked and slide it to the other corner of the agar plate. Sterilized your loop again using the flame and grab the last end of the previously streaked and streak the last corner of the agar plate. This should have four corners the fourth corner being the most diluent will have the most isolated colony forming.
Dilution series: Use microcentrifuge tubes for the dilutions, if the final dilution is 10x^4 , you will need 5 microcentrifuge. Label the one as the stock, 10X, 10X^2, 10X^3 and 10X^4, then add 1 ml of the diluent X. Add .9 ml of the diluent to each concentration microcentrifuge and
0.1 ml of the substance that will be diluted on to the first microcentrifuge which is the one labeled as 10X, using the micropipette. Then add 0.1 ml of from the 10X microcentrifuge onto the 10X^2 microcentrifuge and so on until you reach
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